1. Field of the Invention
This invention relates to the solid state joining of metal alloy pieces in order to form an integral structure. Such structures of this type, generally, allow the metal alloy pieces to be joined by local interfacial strain control.
2. Description of the Related Art
In conventional upset welding process, surfaces to be joined are purposely machined flat and smooth in order to obtain an intimate contact at the interface between the surfaces. The objective is to bring the surfaces into intimate contact for breaking down surface asperities and contaminates, in order to have atomic forces provide the bond. It is thought that once the contaminates and oxides are broken up, their redistribution will help the bonding process. While these bonding processes have met with a modicum of success, the surface material close to the stagnation region is not substantially displaced even though the material is subjected to severe strain and large upset welds are made. Therefore, a more advantageous upset welding process, then, would be presented if such amounts of surface material close to the stagnation region were more evenly displaced.
It is apparent from the above that there exists a need in the art for a solid state joining method which is capable of joining metal alloys, and which at least equals the joining characteristics of the known joining processes, but which at the same time substantially displaces the surface material close to the stagnation region. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.